Practical techniques for reducing unsolicited electronic messages by identifying sender's addresses

In a computer system for managing incoming electronic messages for a recipient, a method for categorizing sender's addresses for purposes of determining whether the sender's addresses are authorized for sending electronic messages to the recipient, comprising the acts of:

• receiving incoming electronic messages that include sender's addresses;
• categorizing each of the sender's addresses as being authorized for sending electronic messages to the recipient, unauthorized for sending electronic messages to the recipient, or unconfirmed as to whether the sender's address is categorized as authorized or unconfirmed, at least one of the sender's addresses being categorized as unconfirmed;
• and
• after the act of categorizing, recategorizing said at least one of the sender's addresses from being unconfirmed to either being authorized or unauthorized based on predetermined criteria.

In a computer system for managing incoming electronic messages for a recipient, a method for categorizing sender's addresses for purposes of determining whether the sender's addresses are authorized for sending electronic messages to the recipient, comprising the acts of:

• accessing information that identifies individuals with whom the recipient has corresponded, the information including addresses from which the individuals can send electronic messages;
• processing the information to categorize the addresses from which the individuals can send electronic messages as being authorized for sending electronic messages to the recipient or unauthorized for sending electronic messages to the recipient;
• and
• receiving an incoming electronic message from one of the addresses and filtering the incoming electronic message according to the categorization thereof.

In a computer system for managing incoming electronic messages for a user, a method for managing a data structure that is used to filter incoming electronic messages comprising the acts of:

• sending an outgoing electronic message from the user to a recipient of the outgoing electronic message, the electronic message containing the recipient's address;
• modifying the data structure associated with the system such that the address of the recipient is categorized as being authorized for sending electronic messages to the user;
• receiving an incoming electronic message that includes a sender's address that is the same as the recipient's address, wherein incoming electronic messages are filtered using the data structure;
• and
• based on the recipient's address being categorized as authorized, permitting the incoming electronic message to be received by the user.

In a network system for managing electronic messages for users, the network having multiple computers that receive incoming electronic messages, a method for managing a data structure that is used to filter incoming electronic messages, comprising the acts of:

• receiving an incoming electronic message that includes the sender's address and is addressed to a user of a first client computer of the network system;
• categorizing the sender's address as being authorized for sending electronic messages to the user of the first computer, unauthorized for sending electronic messages to the user of the first computer, or unconfirmed as to whether the sender's address is authorized or unauthorized;
• and
• propagating the categorization of the sender's address with respect to users of other client computers of the network system, such that the sender's address is also categorized as being authorized, unauthorized, or unconfirmed with respect to said users of the other client computers.

In a computer system for managing incoming electronic messages for a recipient, a method for filtering incoming electronic messages using a categorization of the sender's addresses, comprising the acts of:

• receiving an incoming electronic message that includes a sender's address;
• determining whether the sender's address is categorized as being authorized for sending electronic messages to the recipient or unauthorized for sending electronic messages to the recipient;
• if the sender's address is categorized as being authorized, enabling the incoming electronic message to be presented to the recipient;
• and
• if the sender's address is categorized as being unauthorized, performing the acts of:
• segregating the incoming electronic message from other electronic messages that have authorized sender's addresses;
• transmitting an outgoing electronic message to the sender's address reporting on the segregation of the incoming electronic message.

In a computer system for managing incoming electronic messages for a recipient, a method for categorizing sender's addresses for purposes of determining whether the sender's addresses are authorized for sending electronic messages to the recipient, comprising the acts of:

• receiving an incoming electronic message that includes a sender's address;
• sending a request to the sender's address, wherein the request is to be answered only by receiving input from a person, and wherein the request allows the person to input contact information;
• categorizing the sender's address as being authorized for sending electronic messages to the recipient if a correct response is timely received;
• categorizing the sender's address as being unauthorized for sending electronic messages to the recipient if an incorrect response is timely received;
• categorizing the sender's address as being unconfirmed as to whether the sender's address is authorized or unauthorized if no response to the request is received;
• and
• if the response is received and contains the contact information, storing the contact information for use by the recipient.

In a computer system for managing incoming electronic messages for a recipient, a method for filtering incoming electronic messages using a categorization of the sender's addresses, comprising the acts of:

• receiving an incoming electronic message that includes a sender's address, wherein the sender's address includes a domain;
• in response to the incoming electronic message, sending an outgoing electronic message to an address of a manager of the domain requesting information regarding whether the sender's address is a valid address associated with the domain;
• if the sender's address is a valid address, enabling the incoming electronic message to the recipient;
• and
• if the sender's address is not a valid address, segregating the incoming electronic message from other electronic messages that have sender's addresses that have already been categorized as being authorized for sending electronic messages to the recipient.